This invention is generally directed to a novel air ride suspension system for a light duty trailer. More particularly, the invention contemplates a novel air ride suspension system for a light duty trailer which dissipates normal road vibrations and stress to provide a safe, smooth and longer lasting suspension, thereby resulting in an improved ride over prior art suspension systems, improved performance for light duty trailers, such as aluminum and steel gooseneck trailers, recreational vehicle trailers, fifth wheel travel trailers, and improved life span of the light duty trailer.
U.S. Pat. No. 5,362,095 to Eveley discloses a prior art air ride suspension system. In the ""095 patent, upper and lower leaf springs are pivotally connected at their front ends to a tower which is connected to an underside of the light duty trailer. An air spring is mounted between the underside of the light duty trailer and the rear end of the upper leaf spring. The axle is mounted to the upper and lower leaf springs. A shock absorber is provided between the tower and the axle.
In operation, if no bumps or ruts are encountered, the leaf spring remains generally horizontal relative to the underside of the light duty trailer. If one or both of the tires encounter a bump in the road, the rear end of the leaf springs move upwardly relative to the underside of the light duty trailer and the air spring and the shock absorber compress. If one or both of the tires encounter a rut in the road, the rear end of the leaf springs move downwardly relative to the underside of the light duty trailer and the air spring and the shock absorber expand.
With this prior art design, the air spring can expand to its maximum allowable distance indicated by the air spring manufacturer and can be torn apart during use. In addition, the design does not prevent lateral movement of the leaf spring and subsequent lateral movement of the air spring and the shock absorber during use of the light duty trailer even during turning or backing up of the light duty trailer which can cause damage to the air spring and the shock absorber. Moreover, the design does not provide lateral stability through the extent of vertical travel of the leaf spring, which can result in poorer stability for and reduced torsion on the leaf spring, the air spring and the shock absorber.
The present invention provides a novel air ride suspension system for a light duty trailer, which overcomes the problems presented in the prior art and which provides additional advantages over the prior art. These advantages will become clear upon a reading of the attached specification in combination with a study of the drawings.
A general object of the present invention is to provide a novel air ride suspension system for a light duty trailer.
Another general object of the present invention is to provide a novel air ride suspension system for a light duty trailer, particularly a recreational vehicle trailer, gooseneck or fifth wheel travel trailer, which is primarily designed for axle capacities ranging in size from 3000 lbs. to 8000 lbs.
Yet another general object of the present invention is to provide a novel air ride suspension system for a light duty trailer which dissipates normal road vibrations and stress to provide a safe, smooth and longer lasting suspension, thereby resulting in an improved ride over prior art suspension systems, improved performance for recreational vehicle trailers, aluminum and steel gooseneck trailers, fifth wheel travel trailers, and improved life span of the light duty trailer.
An object of the present invention is to provide a novel air ride suspension system which uses a limiting assembly to secure a rear end of a spring member to a frame of the light duty trailer.
Another object of the present invention is to provide a novel air ride suspension system which uses a limiting assembly to secure a rear end of a spring member to a frame of the light duty trailer to prevent lateral movement of the spring member and subsequent lateral movement of the air spring and the shock absorber during use of the light duty trailer even during turning or backing up of the light duty trailer.
A further object of the present invention is to provide a novel air ride suspension system which uses a limiting assembly to secure a rear end of a spring member to a frame of the light duty trailer to provide lateral stability through the extent of vertical travel of the spring member, thereby resulting in better stability for and reduced torsion on the spring member, the air spring and the shock absorber.
Yet a further object of the present invention is to provide a novel air ride suspension system which uses a limiting assembly to secure a rear end of a spring member to a frame of the light duty trailer to retain the spring member at a predetermined distance from the underside of the light duty trailer, thereby preventing the air spring from being torn apart during use which could happen if the distance the spring member travels exceeds the maximum allowable distance indicated by the air spring manufacturer.
An even further object of the present invention is to provide a novel air ride suspension system which uses a shock-absorber to slow the reaction time of the air spring and to prevent the air spring from jumping back up when the expansion of the air spring is no longer needed.
Yet another object of the present invention is to provide a compact air ride suspension system that is commensurate in length with the tires of the light duty trailer.
A specific object of the present invention is to provide a novel air ride suspension system which is especially useful when hauling horses and delicate cargo and a recreational vehicle trailer.
Briefly, and in accordance with the foregoing, the present invention discloses a suspension system for a light duty trailer. The suspension system includes a pair of modules, with each module being provided on an end of the light duty trailer axle. Each module includes a spring member, preferably a leaf spring, a.tower for connecting a front end of the spring member to an underside of the light duty trailer, an air spring connected between the underside of the light duty trailer and the spring member, and a limiting assembly, preferably a double-hinged spring shackle assembly, for connecting a rear end of the spring member to the underside of the light duty trailer. The front end of the spring member is pivotally connected to the tower. The rear end of the spring member is pivotally connected to the limiting assembly. The axle is connected to the spring member. A shock absorber is provided between the underside of the light duty trailer and the axle. In operation, if no bumps or ruts are encountered, the spring member remains generally horizontal relative to the underside of the light duty trailer. If one or both of the tires encounter a bump in the road, the rear end of the spring member moves upwardly relative to the underside of the light duty trailer and the air spring and the shock absorber compress. If one or both of the tires encounter a rut in the road, the rear end of the spring member moves downwardly relative to the underside of the light duty trailer and the air spring and the shock absorber expand.